The horseshoe vortex system is a simple vortex model for an aircraft or lifting body which fits a box-shaped vortex system out from the wing. This is made up of the wing vortex, trailing vortices (see trailing vortex) and starting vortex. The latter is a vortex formed due to changes in the vorticity of the wing vortex, i.e due to changes in airspeed.
I can't honestly think of a good example for you. Sorry